package web25;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet Filter implementation class ImageFilter
 */
public class ImageFilter implements Filter {

	public void init(FilterConfig config) throws ServletException {
	}

	public void doFilter(ServletRequest req, ServletResponse res,
		FilterChain chain) throws IOException, ServletException {

		HttpServletRequest request = (HttpServletRequest) req;
		HttpServletResponse response = (HttpServletResponse) res;

		String referer = request.getHeader("Referer");

		if (referer == null || !referer.contains(request.getServerName())) {

			request.getRequestDispatcher("error.jpg").forward(request,
					response);

		} else {

			chain.doFilter(request, response);
		}

	}

	public void destroy() {
	}
}
